Pressure developing and driven tool.



A. PALMROS.

PRESSURE DEVELOPING AND DRIVEN TOOL.

APPLICATION FILED JUNE 17. 1910.

1,148,]L 8a Patented July 27, 1915.

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I A. PALMROS.

PRESSURE DEVELOPING AND DRIVEN TOOL.

APPLICATION FILED JUNE 17. 1910.

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Patented July 27, 1915.

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ALEXANDER PALMROS, OF SYRACUSE, NEW YORK, ASSIGN'OR TO THE PNEUMELEGTRIO MACHINE COMPANY, OF SYRACUSE, NEW YORK, A CORPORATION OF NEW YORK.

PRESSURE DEVELOPING AND DRIVEN TOOL.

Specification of Letters latent.

Iatented July 27', 1915.

Application filed June 17, 1910. Serial No. 567,442.

To all whom it may concern Be it known that I, ALEXANDER PALMROS, a citizen of Finland, and resident of Syracuse, in the county of Onondaga and State of New York, have invented certain new and useful Improvements in Pressure Developing and Driven Tools, of which the following is a specification.

My present invention relates to improvements in the construction of that type of tools for percussion machinery in which a tool carrying member is driven forward by the expansive force of compressed air developed by means contained within the machine.

In my application for Letters Patent, filed November 25, 1905, Serial No. 289,127, I have disclosed and broadly claimed a machine embodying a cylinder, a motor driven pressure developing piston, and a pressure driven tool carrying piston; the motor driven piston, for each working stroke of the machine compressing a charge of air from which the percussive stroke of the machine is developed, by releasing the charge and permitting it to act expansively against the tool carrying piston which has in the meantime been suitably retracted; the illustrative embodiment disclosed in said application, also including the features of causing the motor driven piston, by its rearward stroke, to compress the charge of air behind it, and at the same time to retract the tool carrying piston.

According to my present invention, which embodies the same broad principle of operation, I provide a storage chamber into which the successive charges of air are forced and from which they are released, to develop the percussive strokes of the machine, it being thus practicable to develop compression on the forward stroke of the motor driven piston, by displacing air from the space between the pistons, after each percussive stroke is delivered, with the advantages of more evenly distributing the work on the motor driven piston, avoiding the necessity of exhausting the expanded charge of air after each stroke, and of drawing in a complete new charge foreach stroke, with increased introduction of dust into themachine, and insuring the greater pressure against the tool carrying piston, in forcing it to the limit of its forward stroke when it meets with undue resistancein-the mineral.

According to the embodiments selected for illustrating my invention, the storage chamber is constructed either on the cylinder or in one of the pistons (preferably the motor driven piston). In either embodiment the feature of releasing the charge of air from the arrival of the motor driven piston at or near its rearward limit and the feature of retracting the tool carrying piston by the motor driven pistons, are re tained.

My present invention consists in means for accomplishing the ends above outlined, and certain novel features of construction incident thereto.

In the accompanying drawings, several embodiments of my present invention are shown by way of illustration, Figure 1 being a side elevation of an electro-pneumatic coal puncher or mining machine selected for illustrative embodiment of my invention, the working cylinder and one of the pistons being shown in axial section, and the storage chamber in this type being con structed in the wall of the cylinder; Fig. 2 is a detail sectional view of a manually operated drill in which the principles of the invention are embodied; Fig. 3 is a detail sectional'view illustrating a portion of the feed screw of the drill shown .in Fig. 2; Fig. iis a section upon line H of Fig. 3, and, Fig. 5 is a detail view illustrating a ratchet connection between the operating handle and a worm gear shaft of the drill shown in Fig. 2. Fig. 6 a transverse section of Fig. 1 at port 9.

Like numerals designate corresponding parts in all of the figures of the drawing.

Referring to the drawing, A represents the housing of an electric motor, which carries a suitable current controller. B and has transmitting gears C, suit-able for converting the rotary motion of the motor armature, into a right line reciprocating movement, and D represents the pressure developing and utilizing portion of the machine.

Section D of the machine comprises a cylinder-1 containing a piston 2 whose rod 3 is connected to the gearing C, and a piston 4 whose rod 5 is to be understood as carrying or adapted to be connected with the tool or bit to be used. When the pistons are in opposite ends of the cylinder, and the piston 2 moves forward, it compresses air inithe space between the-pistons and displaces the charge of air thus compressed through a port 6 guarded by check valve 7, whence it passes into a storage chamber 8, (Fig. 1) constructedin the wall of the cylinder 1.. When the motion of the piston 2 is reversed, and it rarefies the air behind the piston 4, the'latter is driven rearward by atmospheric pressure entering through a port 11, and this continues until retracting movement in the piston 4 is sufficiently developed, when a port 12- is uncovered by piston 2, which admits atmospheric air to overcome. the rarefaction. The pistons continue to move rearward until piston 2 opens a port 9, the port 9 being controlled by the deep iange 10 of piston 2 in Fig. 1, whereupon the charge of air stored under pressure in the storage chamber will be suddenly released into the inter-piston space and will act expansively against the piston 4 and drive the latter forward to develop its percussive stroke. Air in front of piston 4 escapes through ports 13, which are located sufficiently in the rear of the forward end of the cylinder to insure an air cushion for limiting the forward movement of said piston 4. A check valve 14 prevents outflow of air through port 11. 15 represents a housing for the ports 11 and 13 and the check valve 14, in Fig. 1.

To avoid loading the piston 2 by'alternate rarefaction and compression on its rear side, the cylinder 1 maybe provided with a port 20 as shown in Fig. 1, and if desired, this port may be provided witha valve 21', closing against internal pressure, so that while opening freely to avoid retarding the forward movement of piston 2, it may close on the back stroke so as to compel the fresh air sucked in at each forward stroke, to find its escape through the motor housing as sug gested by arrows, and thus keep down the temperature of the motor. i

In Figs. 2, 3,- 4, and 6, the manually operated drill, embodying certain of the principles of the invention, is illustrated. Referring particularly to these figures, designates a shaft carrying a spiral gear A handle is loosely mounted upon the shaft 33, and a collar 36 fast with the shaft has a ratchet recess 37 formed therein which is engaged'by a pawl pin 38. A spring 39 bears behind said pawl pinand normally tends to force the same into' said recess 37. This is to prevent the operator from turning the drill backward and also permits the mechanism to continue to revolve even though the operator ceases -to turn the handle.

The spiral 1 gear 34 meshes vwith a spiral gear 40 which is fast upon a shaft 41. This shaft carries a gear wheel 42 which meshes with a pinion 43 upon a crank shaft 44. This crankshaft preferablycarries a balance wheel 45.- A connecting rod 46 is actu pawl 57.

illustrated in Fig. 4.

ated by a crank 47 and imparts reciprocatory movement to a piston 48. A dolly49 is slidably disposed in a barrel 50 in which the piston 48 travels. A storage chamber 51 receives the air that is forced past a check valve 52 upon the forward stroke of the piston48. When the piston is retracted sufficient to uncover the port 53, the air stored within the chamber 51 is released between said piston and the dolly 49, and causes said dolly to deliver a percussive blow upona drill 54. A feed screw 55 serves to feed the drill forward in the usual manner. This feed screw is provided with ratchet teeth 56 (see Fig. 4) that are engaged by a small A swinging block 58 is mounted upon the feed screw and the pawl 57 is pivoted to this block. A spring 59 normally tends to move the pawl into engagement with the ratchet teeth. In Fig. 6, however, the block is shown swung into a position where the tail of the pawl 57 engages the wall of the casing 60, whereby the pawl is held out of engagement with the ratchet teeth, and at this time the feed screw may be reversed by means of a crank (not shown) applied to the angular end 61 of the feed screw. A spring 62 normally tends to move the swinging block 58 to the position One end of this spring engages in notches 62 of the casing and the other end of the spring engages the swinging block 58. The tension of the spring may be varied by engaging in the desired one of the notches 62.

Ordinarily the swinging block is prevented from swinging far enough to the left in Fig. 4 to move the pawl 57 out of engagement with the ratchet teeth 56 by means of a stop bar 63. This bar is provided with an operating knob 64 which acts much after the manner of an ordinary door bolt. That is, it may be moved longitudinally and may be turned to bring the shank of the knob 64 into any one of the transverse channels 65. This stop bar serves to variably limit the throw of the swinging block and consequently serves to adjust the movement of the feed screw.

A downwardly projecting lug 66 upon the gear wheel 41 strikes against the extension 67 of the swinging block 58 as said gear wheel rotates and swings the block toward the right in Fig. 4, whereupon the pawl 57 engages the teeth 56 and imparts partial rotation to the feed screw. As soon as the lug 66 clears the extension 67, the spring 62 acts to turn the swinging block to its limit of movement toward the left in Fig. 4, this limit of movement being determined by the position of the stop bar 63.

Having thus described my invention, what I claim as new therein and desire to secure by Letters Patent is '1. A reciprocating tool comprising fluid pressure developing and driven members, a

common cylinder for said members, a fluid pressure storage chamber situated to receive fluid under pressure from said pressure developing piston during its forward stroke, a valve controlled intake port and a discharge port, said pressure developing member having a rearward extension for closing said discharge port during the greater part of its stroke, said ports establishing communication between the cylinder of said members and said storage chamber.

2. A fluid-pressure driven percussion tool comprising pressure developing and driven pistons, a common cylinder in which said pistons are housed, a pressure-medium storage chamber carried by but separated from said cylinder, said chamber situated to receive fluid under pressure during the forward stroke of said pressure developing piston, said cylinder having intake and discharge ports opening into the chamber at points in rear of the rear and forward limits of the pressure driven piston, respectively, and a check valve controlling said discharge port, said pressure developing piston having a cylindrical extension wherewith to close the intake port during the main part of its stroke.

3. A fluid-pressure driven percussion tool comprising pressure developing and driven pistons, a common cylinder in which said pistons are housed, a pressure-medium storage chamber carried by but separated from said cylinder, said chamber situated to receive fluid under pressure during the forward stroke of said pressure developing piston, said chamber having intake and discharge ports opening into the cylinder at points in rear ofthe forward and rear limits of the pressure driven piston, respectively, said intake port being provided with a check valve, the length of said pressure de veloping piston being slightly less than that of its complete stroke whereby the discharge port will be closed by said developing piston during the greater part of its stroke.

4. A fluid-pressure driven percussion tool comprising pressure-developing and driven pistons, a common cylinder in which said pistons are housed, a pressure-medium storage chamber carried by said cylinder and having intake and discharge ports opening into the cylinder at points in rear of the forward and rear limits of the pressure driven piston, respectively, said intake port being provided with a check valve, and said pressure developing piston having a rearwardly extending flange, closing the discharge port when the pistons are in forward position.

5. A fluid-pressure driven percussion tool comprising pressure developing and driven pistons, a common cylinder in which said pistons are housed, a pressure-mediun1 storage chamber carried by said cylinder and having intake and discharge ports opening into the cylinder at points in rear of the forward and rear limits of the pressure driven piston, respectively, said intake port being provided with a check valve, whereby retracting influence develops between the pistons on the return stroke, and the housing being provided with an inwardly opening valved port from atmosphere located to destroy vacuum between the pistons after retraction is developed.

The foregoing specification signed at New York city, N. Y., this 9th day of June, 1910.

ALEXANDER PALMROS.

In presence of two witnesses:

JOHN L. WAGNER, M. G. CRANroRD.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. G. 

